This disclosure relates to a turbine blade for use in, for example, an industrial gas turbine engine. More particularly, the disclosure relates to an air seal strip.
Industrial gas turbine engines include blades having a shank provided between a root and a platform, which supports an airfoil. The root is received in a rotor slot to secure the blade relative to a shaft, which transmits the rotational input to or from the blades. The shank is relatively long, and a portion of the shank may be received in a slot within a turbine rotor, which also receives the root.
One type of root includes multiple undulations configured in a fir-tree shape. A seal is typically provided between the root and the rotor slot to prevent flow from bypassing the blade during engine operation, which would reduce engine efficiency. In one example, a soft aluminum material is adhered to an underside of the undulations at a trailing edge side of the root. The aluminum material is deformed when the turbine blade is inserted into the slot to provide the seal. However, aluminum material is not provided on the shank. Cover plates at the forward and aft locations of the blade and within the slot are relied upon to provide a seal.